The Global Positioning System (“GPS”) includes a network of GPS satellites that orbit the Earth at an altitude of approximately 20,000 km. Typically, each GPS satellite broadcasts radio signals at regular intervals that a GPS receiver can receive and process to determine its location. As currently implemented, any GPS receiver on the Earth's surface should be in range of least four GPS satellites at any given time. Transmitted GPS radio signals include precise information about the satellite's position and time of transmission. Based on the received signals, a GPS receiver determines its location by calculating the distance from each of the satellites by calculating the amount of time that each respective signal took to arrive at the receiver.
Many wearable technologies incorporate GPS to allow for location-based functionalities. With advances in computing power and miniaturizing of electronic devices, wearable technology promises to interweave into everyday life. Although the possibilities are many, wearable technology can take the form of wearable computers, item location trackers, activity trackers, health monitors, and so-called smartwatches to name a few.